What Is Calorie Deficit?

Posted on 18/03/2025

The shortest answer to that is – THE ONLY WAY TO LOSE WEIGHT and that is the first law of thermodynamics – Energy cannot be destroyed, created or lost, but it can be transformed from one form to another. And adding to that the facts from human anatomy, our bodies store the excess energy from food as body fat. Simple. So to make your body to burn fat, the amount of intake calories have to be less than the ones used. And how we use our calories? I already explained that, the link is just here.

The first thing that comes to mind when a person wants to become thinner and lighter is … EAT LESS FOOD. Logical. And that is a completely valid way to make it. The problem here is that for some unknown reason we all want that to happen overnight. Or yesterday. Or even last week, goddamn those love handles. Sorry, to disappoint, but if you are too aggressive with the deficit level, you will quit early, binge eat all of the cookies at home and feel miserable, tired, angry and depressed all day each day.

There are plenty of scenarios how you can actually achieve, and most importantly, maintain a reasonable level of calorie deficit and here are all of them:

Option 1 is the simplest one, eat less food. In this manner, the total calorie intake is less than the total calories burned and the body is using all resources available. That includes not only the stored body fat, in this manner the weigh loss also consists of decreased amount of muscle mass, decreased bone density. So at some point you will start to feel weaker and despite the fact that you are lighter, you may not like the results in the mirror. You will also be more prone to injuries and the worst part is that when you decide it is over and start eating as you used to eat before … the weight gain will be 95% body fat.

And even if you were 80 kg in the beginning, then went down to 70 and then jumped back to 75 … you will be fatter at 75, compared to what you were at 80. And here is why all nutrition-only based plans … do not work in the long run. Eating less amounts of the same foods you ate since child takes you back at square 1. I am strong believer in making small changes that result in huge impact later on and that is the beauty of nutrition. And this is coming from a former food blogger and chef, you should give me the benefit of the doubt. At least 🙂

Option 2 plays with the components of the food we eat. It is a fact that a calorie is a calorie, we cannot bend and twist the laws of nature. But we have to take into the equation our digestive system too. Because food comprises of proteins, fats and carbohydrates and they carry different calories per gram.

1 gram of fats is 9 calories. Our system digests and metabolises fats pretty easy and the net effect for the body is roughly the same (2% loss due to thermic effect of food). 1 gram of carbs is 4 calories and the losses for metabolization are also negligeable, 6% so the net effect is 3.7 calories. 1 gram of protein is also 4 calories, but it takes 25-30% to break down the long chains into usable amino acids. So the net effect is 2.6 calories. Going back to carbs, the fibres (especially the insoluble ones) are counted as carbs. But they are not digested at all. Their net effect for the body is 0.2 calories per gram.

So opting for Option 2 is a clever way to go. You will be eating the same amount of calories, but you should replace some of your previous food choices with ones that are rich in protein and rich in fibres. There are easy swaps available, the first that comes to mind is ditching the milk from your breakfast and introducing skyr, quark or protein powder. Or something else. Also consuming foods rich in fibres, let’s not forget that. The first that will come to your mind is cucumbers, tomatoes and lettuce, but my recommendation here would be all types of berries, chia, legumes and beans. Fun fact – dark chocolate has 10.9% fibres.

And because you will be increasing the amount of protein, the weight loss effect will be mainly body fat. Amino acids from the protein will be used to preserve the lean muscle mass and the bone density. The downside of this otherwise healthy approach is that it takes the longest. The deficit created will be something below 10% and if you are 80 kg person, this will result in 1 kg down each two months.

Going back to the article with “Where calories go“, there is one thing called “Non Exercise Activity” and that is the Option 3 for how to create a calorie deficit. A sustainable one.

The most common, the simplest and the cheapest way to increase your activity is a natural ability we all have and under-use … WALKING. An average walk of 15 min will result in a slightly elevated, but steady heart rate between 103 and 119 beats per minute and will make you “burn” additional 100 kcals. Make those walks two per day and that is 3000 steps more and 200 kcals less.

200 kcals is 10% of the total average daily expenditure and it will result (in the same hypothetical scenario of a 80 kg person) in additional loss of 0.5 kg per month. So by now, combining the 2 and 3 as options, we can certainly say that in 10 months time the weight will go down from 80 to 70 kg and the majority of the loss will be body fat. And because the process was slow and steady, most certainly the new weight will be sustainable and easy to maintain for life.

I also have another viable option that when applied in moderation, will speed up the process of weight loss without jeopardising the long-term effects and will not make you lose lean muscle mass. And that is a combination of all three listed above – eat less food, change food sources, walk. All those stack one on top of another and increase the deficit.

And of course, the cherry on the top, the limousine of weight loss. Add gym or home trainings with weights. Here the benefits are almost countless. Increased amount of protein will provide building bricks for new muscles and will keep you full and energetic during the day. Each kilogram of weight you lose will decrease the pressure on your knees with 4 kg and on your hips with 6 kg. You will not only feel, but also look slender, the clothes will start fitting in a different way. No wonder you will replace your wardrobe in 6 months. Weights training and the benefits are countless and deserve a separate article, coming soon.

It really is not that hard. Two small changes in eating and daily activity. Slightly less food. Gym two or three times a week. Or in-home exercises. Your choice. And in three months you will start to see the results. You might be a brand new person in six months. And who knows, a fellow coach in a year.

Thank you for reading this till the end. I know you found it useful, so please share using the buttons below. Or book your call with me (free consultation) and we will make it a beginning of something beautiful. You. Your new “ME”

Share this article:

Next Reading

07/04/2025

Progressive Overload

In the world of strength training and personal fitness, understanding the principle of progressive overload is crucial for making continuous gains. While many people focus on merely increasing weights, the finer details of training techniques—such as rep ranges and Reps In Reserve (RIR)—can make […]

Begin Your Journey Today

I’ve been where you are. I know what it feels like to want change but not know where to start. Let’s make sure this time is different—sustainable, enjoyable, and built around you.

Still Wondering?

Book a free online consultation with me.